A loading dock for a vehicle such as a trailer truck or box truck commonly includes an overhead door frame of a width and height sufficient to accommodate the interior region of the trailer cargo area. When the overhead door is closed, the truck backs towards the loading dock until the rear of the cargo compartment engages the dock. The cargo compartment of the truck is thus roughly aligned with the opening of the loading dock. The truck may have an overhead door or, more commonly, hinged panel doors that swing open and are stowed against the side of the trailer.
Dock levelers are utilized to compensate for height differences between a dock platform and the bed of the parked vehicle to permit forklift trucks and personnel to readily move on and off the vehicle during loading and unloading operations. A typical dock leveler is mounted within a pit and has a deck pivotally connected at its rear edge to a frame mounted within the pit for varying the height of the dock leveler in order to compensate for the height differences. An extension plate or lip is typically pivotally connected to the front edge of the deck for spanning the distance between the rear end of the vehicle bed and the outer front end of the deck and permitting forklift trucks and personnel to safely load and unload the truck without difficulty.
The deck is adapted to pivot between downwardly inclined or lowered positions, a horizontal or level position, and upwardly inclined or raised positions relative to the dock platform. When the dock leveler is not in use, the deck is substantially coplanar with the adjacent, upper surface of the dock. To permit such movement of the deck, a gap is typically formed along the adjacent edges of the deck and loading dock floor.
The loading dock includes a bumper system to cushion the impact of the rear of the vehicle making contact with the dock. Typically, a bumper system includes two bumpers, one on either side of the leveler pit. The bumper is secured to a vertical wall of the loading dock, just below the floor level. The bumper is made from laminated strips of rubber and extends away from the wall about twelve inches.
Sealing the cargo area of the vehicle from outdoor environmental conditions can be an important requirement of a loading dock structure, particularly when the cargo and the receiving dock are refrigerated. To address this need, dock seals and dock shelters have been designed to prevent the ingress of outdoor environmental conditions or contaminants (e.g., rain, snow, wind, hot/cold temperatures, insects, animals, etc.) into the interior of the dock area and cargo area of the vehicle during the loading or unloading of the vehicle. Dock shelters and dock seals also address the need to prevent the egress of refrigerated air from within the loading bay and/or vehicle cargo area to the outdoor environment. Typically, dock seals and dock shelters include vertical side members along both sides of the loading bay door and a horizontal header extending across the top of the door. Because the dock leveler pit is deeper than the rear cargo frame of the vehicle, dock seal and dock shelter systems do not include lower horizontal sealing members.